This invention concerns preparing ferrous metal substrates for coating, more particularly for coating with aqeuous dispersions containing fluorocarbons.
Triethanolamine has been used in small quantities, such as about 1%, to aid in dispersing pigments in fluorocarbon primer compositions. Larger amounts, such as 4%-41/2% of triethanolamine have been used in fluorocarbon topcoat coating compositions containing fugitive coalescing agents which decompose after aiding in the coalescence of the fluorocarbon during curing of the coating at elevated temperatures. (Parts and percentages herein are by weight except where indicated otherwise.).
Several U.S. patents disclose fluorocarbon coating compositions which can be used in conjunction with the present invention, including U.S. Pat. Nos. 4,011,361--Vassiliou and Concannon (1977); 4,016,125--Vassiliou and Concannon (1977); 4,039,713--Vassiliou (1977); 4,049,863--Vassiliou (1977); 4,070,525--Vassiliou and Concannon (1978); 4,087,394--Concannon (1978); and 4,123,401--Berghmans and Vary (1978). These patents are incorporated herein by reference.
Such compositions are useful in coating cookware and other types of substrates.